Edison was speaking about his work on the perfection of the light bulb. Instead of focusing on how many times he had failed, he saw it as how many times he had eliminated what would didn't work, putting him that much closer to success. How often do we let one failure, or two or three stop us?
"If everything is under control, you're going too slow." -Mario Andretti.
I like slow, comfortable and easy going. But not much gets done that way.